The management of bandwidth in a network includes allocating available bandwidth efficiently by taking into consideration the different types of network traffic and quality of service requirements. Bandwidth allocation and deallocation may cause bandwidth fragmentation, which may result in link unavailability even when sufficient aggregate bandwidth is available. The continuous setup, deletion and re-routing of connections in a network may cause the network's performance to suffer due to bandwidth fragmentation. For example, a network may utilize only 40% of its available bandwidth to route connections, referred to herein as sub-network connections (“SNCs”), because the remaining 60% may be divided into bandwidth fragments that are too small to route an SNC.
Bandwidth fragmentation may affect routing significantly and may delay allocation of cost effective bandwidth. A sub-network connection (“SNC”) setup request may be treated differently depending on the bandwidth requirements of the SNC. For example, bandwidth fragmentation may cause SNCs with a low bandwidth requirement to obtain bandwidth easily, while SNCs with high bandwidth requirements may have a more difficult time obtaining bandwidth.
Given continuous bandwidth fragmentation, in order to maintain a desired network performance level, network administrators schedule automatic bandwidth defragmentation operations. While some networks support automatic bandwidth defragmentation, some networks, such as Generalized Multi-protocol Label Switching (GMPLS) networks, require bandwidth defragmentation to be performed manually. As such, connections have to be manually torn down and moved to a different link. Many times, for networks such as Synchronous Optical Network (SONET) and Synchronous Digital Hierarchy (SDH) networks, a defragmentation operation may not be enough to improve the performance of the network and additional packing algorithms may need to be employed. Even though bandwidth defragmentation may improve a link's performance, network defragmentation disturbs traffic on the lines.
It is therefore desirable to have a method and system to avoid bandwidth fragmentation on a network link.